In practice very many methods to send data are known, particularly through a network. An example are digital data that are sent through the internet, but also digital telephone signals, such as for instance in case of cordless GSM telephones.
In practice there are also various methods known for multiplexing digital data.
The data are sent via a medium in the form of data packets. This can take place via a physical cabling in for instance copper or glass fibre, or via infrared or radio waves.
Because the capacity, often coupled to bandwidth, of the media over which the data are being sent mostly is too small, the data are often compressed. However, this has often appeared not to be sufficient.
Additionally many of these methods are aimed at optimising the data transfer between two computers.